Relationship between Panicle Weight per Plant and Cumulative Water Stress in Rice

Abstract

Decrease of panicle weight per plant in rice in proportion to cumulative water stress (an integrated estimate of the degree and duration of water stress) has been demonstrated in rice subjected to increasing water stress imposed at the early stages of panicle development. Since yield decrease under drought is proportional to yield without drought, it was expected that the decrease of panicle weight per plant by a unit change of cumulative water stress might be proportional to panicle weight per plant under submerged soil condition. To prove this hypothesis, we conducted an experiment in which the relationship between panicle weight per plant and cumulative water stress was examined. Two rice cultivars, one wetland (Koshihikari) and another dryland (Sensyou), were grown in pots differing in their size and fertilizer level. The plants were subjected to different water treatments started either at the stage of the secondary-branch primordia differentiation or at heading and anthesis. Control plants were kept continuously submerged. The decrease in panicle weight per plant under drought was proportionally related to the cumulative water stress in plants subjected to water stress during heading and anthesis as was during early stages of panicle development. The linear regression coefficient between the panicle weight per plant and cumulative water stress was also proportional to the panicle weight per plant under submerged condition. In other words, the panicle weight per plant under water stress G (g plant-1) can be related to the cumulative water stress CWS (MPa · day) by: [formula omitted] where Go is the panicle weight per plant under submerged condition (g plant'1) and K is the constant defined as water stress susceptibility (MP-1 day-1).

title = "Relationship between Panicle Weight per Plant and Cumulative Water Stress in Rice",

abstract = "Decrease of panicle weight per plant in rice in proportion to cumulative water stress (an integrated estimate of the degree and duration of water stress) has been demonstrated in rice subjected to increasing water stress imposed at the early stages of panicle development. Since yield decrease under drought is proportional to yield without drought, it was expected that the decrease of panicle weight per plant by a unit change of cumulative water stress might be proportional to panicle weight per plant under submerged soil condition. To prove this hypothesis, we conducted an experiment in which the relationship between panicle weight per plant and cumulative water stress was examined. Two rice cultivars, one wetland (Koshihikari) and another dryland (Sensyou), were grown in pots differing in their size and fertilizer level. The plants were subjected to different water treatments started either at the stage of the secondary-branch primordia differentiation or at heading and anthesis. Control plants were kept continuously submerged. The decrease in panicle weight per plant under drought was proportionally related to the cumulative water stress in plants subjected to water stress during heading and anthesis as was during early stages of panicle development. The linear regression coefficient between the panicle weight per plant and cumulative water stress was also proportional to the panicle weight per plant under submerged condition. In other words, the panicle weight per plant under water stress G (g plant-1) can be related to the cumulative water stress CWS (MPa · day) by: [formula omitted] where Go is the panicle weight per plant under submerged condition (g plant'1) and K is the constant defined as water stress susceptibility (MP-1 day-1).",

T1 - Relationship between Panicle Weight per Plant and Cumulative Water Stress in Rice

AU - Tsuda, Makoto

AU - Yamane, Yuji

AU - Takami, Shinichi

PY - 1993

Y1 - 1993

N2 - Decrease of panicle weight per plant in rice in proportion to cumulative water stress (an integrated estimate of the degree and duration of water stress) has been demonstrated in rice subjected to increasing water stress imposed at the early stages of panicle development. Since yield decrease under drought is proportional to yield without drought, it was expected that the decrease of panicle weight per plant by a unit change of cumulative water stress might be proportional to panicle weight per plant under submerged soil condition. To prove this hypothesis, we conducted an experiment in which the relationship between panicle weight per plant and cumulative water stress was examined. Two rice cultivars, one wetland (Koshihikari) and another dryland (Sensyou), were grown in pots differing in their size and fertilizer level. The plants were subjected to different water treatments started either at the stage of the secondary-branch primordia differentiation or at heading and anthesis. Control plants were kept continuously submerged. The decrease in panicle weight per plant under drought was proportionally related to the cumulative water stress in plants subjected to water stress during heading and anthesis as was during early stages of panicle development. The linear regression coefficient between the panicle weight per plant and cumulative water stress was also proportional to the panicle weight per plant under submerged condition. In other words, the panicle weight per plant under water stress G (g plant-1) can be related to the cumulative water stress CWS (MPa · day) by: [formula omitted] where Go is the panicle weight per plant under submerged condition (g plant'1) and K is the constant defined as water stress susceptibility (MP-1 day-1).

AB - Decrease of panicle weight per plant in rice in proportion to cumulative water stress (an integrated estimate of the degree and duration of water stress) has been demonstrated in rice subjected to increasing water stress imposed at the early stages of panicle development. Since yield decrease under drought is proportional to yield without drought, it was expected that the decrease of panicle weight per plant by a unit change of cumulative water stress might be proportional to panicle weight per plant under submerged soil condition. To prove this hypothesis, we conducted an experiment in which the relationship between panicle weight per plant and cumulative water stress was examined. Two rice cultivars, one wetland (Koshihikari) and another dryland (Sensyou), were grown in pots differing in their size and fertilizer level. The plants were subjected to different water treatments started either at the stage of the secondary-branch primordia differentiation or at heading and anthesis. Control plants were kept continuously submerged. The decrease in panicle weight per plant under drought was proportionally related to the cumulative water stress in plants subjected to water stress during heading and anthesis as was during early stages of panicle development. The linear regression coefficient between the panicle weight per plant and cumulative water stress was also proportional to the panicle weight per plant under submerged condition. In other words, the panicle weight per plant under water stress G (g plant-1) can be related to the cumulative water stress CWS (MPa · day) by: [formula omitted] where Go is the panicle weight per plant under submerged condition (g plant'1) and K is the constant defined as water stress susceptibility (MP-1 day-1).